Once reserved for dangerously heavy people, advancements make procedures available to more people

Mahaffey underwent a procedure called POSE, or primary obesity surgery, endolumenal, designed for people who need to lose only a moderate amount of weight.

In another incisionless technique still in the early stages of development, a device is placed in the upper part of the small intestine to create a barrier between food and the wall of the intestines, mimicking the effect of gastric bypass surgery. The device is expected to cost about half as much as gastric banding and one-quarter as much as gastric bypass.

Lowering the cost of surgery will be key to offering an effective weight-loss option to thousands, or millions, more people, Schauer said. The costs of traditional weight-loss surgery vary widely, with average costs ranging from $13,000 to more than $50,000, depending on the type of procedure and the area where it's performed.

Whether insurance companies will welcome the idea of more people receiving bariatric surgery remains to be seen. Weight-loss surgery is now covered by insurance only for those patients who have premium benefits and a BMI of 40 or higher, or a BMI of 35 or higher with obesity-related medical problems. Standard health plans typically don't include coverage of bariatric surgery.

However, insurance companies tend to follow the lead of the Centers for Medicare & Medicaid Services, and last February the federal agency announced that it would approve payment of surgery for people with Type 2 diabetes and a BMI of at least 35.

In November, a consortium of influential medical groups published a consensus statement recognizing the "legitimacy" of bariatric surgery as a treatment for some patients with Type 2 diabetes and noted that surgery may be suited for people with Type 2 diabetes who are not yet morbidly obese -- those with a BMI of 30 to 35.

"I see many patients with BMIs in the low 30s who aren't going to make it much longer," said Kushner, of Northwestern. "If we could get that person to take off 30 or 40 pounds long-term, that would make a tremendous difference."

"There is probably a subset of patient with BMIs under 35 -- those with diabetes, metabolic syndrome, hypertension, severe sleep apnea -- who would benefit substantially from some sort of (surgical) intervention," said Dr. Eric Hungness, a bariatric surgeon at Northwestern Memorial Hospital. The Chicago medical center is offering surgeries to patients who fit that description on a case-by-case basis, he said.

Nearby, at a surgery center at 900 N. Michigan Ave., Myers estimates he has performed more than two dozen lap-band stomach surgeries on patients with BMIs of 30 to 35 in the last several years. More have conditions such as diabetes, high blood pressure or high cholesterol and all pay for the operations themselves.

"This isn't a quick fix or an easy fix," he warned, noting that people have to permanently change their eating, drinking and exercise habits for the procedures to achieve expected weight-loss gains.

Dr. John Baker, president of the bariatric surgery society, said that for people with a BMI of 25 to 30, which is considered overweight but not obese, diet and exercise changes should still be the treatment of choice.

"Even people who have surgery still have to focus on those things," he said. "You have to change your lifestyle and habits for any weight-loss program."